Cutler advocates removing toxins from the body to achieve better health. Since the liver is primarily responsible for removing or detoxifying chemical compounds, either naturally or artificially produced, it makes sense that helping the liver to do its job will help you maintain better liver health. Cutler, however, is selling nothing more than snake oil; by improving your diet and supplementing it with vitamins and minerals in appropriate doses, you can do what he does for a lot less money.
How do we know that Dr. Cutler's Liver and Kidney Cleanse is just snake oil that will not help?
Oh, it will probably do something positive, but you can get a better value for you money and your body by eating foods that contain the necessary compounds for better liver and kidney health.